传统酸面团中优势酵母菌的分离及鉴定

Isolation and Identification of Predominant Yeast from Traditional Sourdough

为充分挖掘性状优良的可用于发酵面制品生产的酵母菌发酵剂菌种资源,采集黑龙江地区私人家庭长期用于馒头等发酵面制品制作的传统自然发酵酸面团,均质化并梯度稀释后,稀释液培养于马铃薯琼脂培养基中,从而对传统酸面团样品中的优势酵母菌进行分离及纯化,并分别对其形成的菌落及菌体细胞特征进行形态学描述,随后提取酵母菌分离菌株的基因组DNA,通过PCR扩增其26S rDNA D1/D2区基因并测序,利用MEGA软件构建同属内菌种的系统发育树,通过亲缘关系远近对酵母菌分离菌株的种属加以鉴定。结果表明:从黑龙江地区采集的5份传统酸面团样品中,共分离出19株酵母菌,其中18株为酿酒酵母,1株为异常威克汉姆酵母,可为工业酵母菌发酵剂菌种的开发提供候选菌株。

In order to fully tap the excellent yeast starter resources which can be used in the production of fermented flour products,in this paper,we collected the traditional natural fermented sour dough which has been used by private families in Heilongjiang Province for a long time,after homogenization and gradient dilution,the diluent was cultured in potato agar medium to isolate and purify the dominant yeast from traditional sour dough samples,the morphology of the colony and cell characteristics of the bacteria was described respectively.Then the genomic DNA of the yeast isolated strain was extracted,and the region of 26S rDNA D1/D2 was amplified by PCR and sequenced.The phylogenetic tree of the same genus was constructed by using MEGA software,and the species and genera of the yeast isolates were identified by their genetic relationship.The results showed that:a total of 19 yeast strains were isolated from 5 traditional sour dough samples collected in Heilongjiang Province,among which 18 strains were Saccharomyces cerevisiae and 1 strain was Wickerhamomyces,which could provide candidate strains for the development of industrial yeast starter strains.